This is my first year of pool ownership. Everything seemed to go fine at first. The pool is a 35k gallon gunite pool. We opened the pool. Shocked and watched it go from disgusting green to grey to cloudy blue to blue. Used chlorine tabs and kept the water balanced from early June on and had no real issues. Than about two weeks ago a storm threw off the PH and alkalinity. Spent some money on alkalinity up chemicals and used the last of my soda ash to restore the balance and by this point the pool got a bit green. Used some shock. No results. Used a lot more shock. Still no results. Another storm came and threw the PH down from 7.4 to 6.1. I gave up. The pool is now swamp green. We are going out of town for a weekend and it is getting too cold to use the pool regularly since we do not have a heater and any time the night time temperatures drop into the low 70s or lower the water is a bit chilly. My question is can I just partially drain the water down to about 2/3 and close the pool in its current disgusting state? I REALLY do not want to spend another $100+ on shock before closing it knowing that I will have to re-shock it when I re-open next spring. MY plan was to drain it down to below the return lines, blow the water out of the return lines and cap them off and put the cover on. Than to drain the filters and pump, open the connection joints for the returns and leave it for the winter. Am I missing anything that needs to be done? I live in Maryland just outside of Washington DC.